Nintendo has been known to dip into its past when looking for the future. Nintendo's newest home console is no different, and many of the Wii U's most exciting new features have closely related Nintendo antecedents in an unlikely source: the oft-overlooked connectivity between the GameCube and Game Boy Advance. With the GameCube-Game Boy Advance link cable the two systems are able to link up and exchange data, and when used creatively this pairing presents players with gameplay possibilities remarkably reminiscent of the kind seen on Nintendo's upcoming console. Nintendo Life looks at some notable examples.
I also used it for transfering Chao from Sonic Adventure to Sonic Adventure 2.
But yeah, it was kinda limited.